Commit | Line | Data |
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65765700 | 1 | /* .eh_frame section optimization. |
c68836a9 | 2 | Copyright 2001, 2002 Free Software Foundation, Inc. |
65765700 JJ |
3 | Written by Jakub Jelinek <jakub@redhat.com>. |
4 | ||
5 | This file is part of BFD, the Binary File Descriptor library. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | #include "bfd.h" | |
22 | #include "sysdep.h" | |
23 | #include "libbfd.h" | |
24 | #include "elf-bfd.h" | |
25 | #include "elf/dwarf2.h" | |
26 | ||
27 | #define EH_FRAME_HDR_SIZE 8 | |
28 | ||
65765700 JJ |
29 | static bfd_vma read_unsigned_leb128 |
30 | PARAMS ((bfd *, char *, unsigned int *)); | |
31 | static bfd_signed_vma read_signed_leb128 | |
32 | PARAMS ((bfd *, char *, unsigned int *)); | |
33 | static int get_DW_EH_PE_width | |
34 | PARAMS ((int, int)); | |
9e2a4898 JJ |
35 | static bfd_vma read_value |
36 | PARAMS ((bfd *, bfd_byte *, int)); | |
37 | static void write_value | |
38 | PARAMS ((bfd *, bfd_byte *, bfd_vma, int)); | |
65765700 JJ |
39 | static int cie_compare |
40 | PARAMS ((struct cie *, struct cie *)); | |
41 | static int vma_compare | |
42 | PARAMS ((const PTR a, const PTR b)); | |
43 | ||
44 | /* Helper function for reading uleb128 encoded data. */ | |
45 | ||
46 | static bfd_vma | |
47 | read_unsigned_leb128 (abfd, buf, bytes_read_ptr) | |
48 | bfd *abfd ATTRIBUTE_UNUSED; | |
49 | char *buf; | |
50 | unsigned int *bytes_read_ptr; | |
51 | { | |
52 | bfd_vma result; | |
53 | unsigned int num_read; | |
54 | int shift; | |
55 | unsigned char byte; | |
56 | ||
57 | result = 0; | |
58 | shift = 0; | |
59 | num_read = 0; | |
60 | do | |
61 | { | |
62 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
63 | buf ++; | |
64 | num_read ++; | |
65 | result |= (((bfd_vma) byte & 0x7f) << shift); | |
66 | shift += 7; | |
67 | } | |
68 | while (byte & 0x80); | |
69 | * bytes_read_ptr = num_read; | |
70 | return result; | |
71 | } | |
72 | ||
73 | /* Helper function for reading sleb128 encoded data. */ | |
74 | ||
75 | static bfd_signed_vma | |
76 | read_signed_leb128 (abfd, buf, bytes_read_ptr) | |
77 | bfd *abfd ATTRIBUTE_UNUSED; | |
78 | char *buf; | |
79 | unsigned int * bytes_read_ptr; | |
80 | { | |
81 | bfd_vma result; | |
82 | int shift; | |
83 | int num_read; | |
84 | unsigned char byte; | |
85 | ||
86 | result = 0; | |
87 | shift = 0; | |
88 | num_read = 0; | |
89 | do | |
90 | { | |
91 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
92 | buf ++; | |
93 | num_read ++; | |
94 | result |= (((bfd_vma) byte & 0x7f) << shift); | |
95 | shift += 7; | |
96 | } | |
97 | while (byte & 0x80); | |
98 | if (byte & 0x40) | |
99 | result |= (((bfd_vma) -1) << (shift - 7)) << 7; | |
100 | * bytes_read_ptr = num_read; | |
101 | return result; | |
102 | } | |
103 | ||
104 | #define read_uleb128(VAR, BUF) \ | |
105 | do \ | |
106 | { \ | |
107 | (VAR) = read_unsigned_leb128 (abfd, buf, &leb128_tmp); \ | |
108 | (BUF) += leb128_tmp; \ | |
109 | } \ | |
110 | while (0) | |
111 | ||
112 | #define read_sleb128(VAR, BUF) \ | |
113 | do \ | |
114 | { \ | |
115 | (VAR) = read_signed_leb128 (abfd, buf, &leb128_tmp); \ | |
116 | (BUF) += leb128_tmp; \ | |
117 | } \ | |
118 | while (0) | |
119 | ||
120 | /* Return 0 if either encoding is variable width, or not yet known to bfd. */ | |
121 | ||
122 | static | |
123 | int get_DW_EH_PE_width (encoding, ptr_size) | |
124 | int encoding, ptr_size; | |
125 | { | |
126 | /* DW_EH_PE_ values of 0x60 and 0x70 weren't defined at the time .eh_frame | |
127 | was added to bfd. */ | |
128 | if ((encoding & 0x60) == 0x60) | |
129 | return 0; | |
130 | ||
131 | switch (encoding & 7) | |
132 | { | |
133 | case DW_EH_PE_udata2: return 2; | |
134 | case DW_EH_PE_udata4: return 4; | |
135 | case DW_EH_PE_udata8: return 8; | |
136 | case DW_EH_PE_absptr: return ptr_size; | |
137 | default: | |
138 | break; | |
139 | } | |
140 | ||
141 | return 0; | |
142 | } | |
143 | ||
9e2a4898 JJ |
144 | /* Read a width sized value from memory. */ |
145 | ||
146 | static bfd_vma | |
147 | read_value (abfd, buf, width) | |
148 | bfd *abfd; | |
149 | bfd_byte *buf; | |
150 | int width; | |
151 | { | |
152 | bfd_vma value; | |
153 | ||
154 | switch (width) | |
155 | { | |
156 | case 2: value = bfd_get_16 (abfd, buf); break; | |
157 | case 4: value = bfd_get_32 (abfd, buf); break; | |
158 | case 8: value = bfd_get_64 (abfd, buf); break; | |
159 | default: BFD_FAIL (); return 0; | |
160 | } | |
161 | ||
162 | return value; | |
163 | } | |
164 | ||
165 | /* Store a width sized value to memory. */ | |
166 | ||
167 | static void | |
168 | write_value (abfd, buf, value, width) | |
169 | bfd *abfd; | |
170 | bfd_byte *buf; | |
171 | bfd_vma value; | |
172 | int width; | |
173 | { | |
174 | switch (width) | |
175 | { | |
176 | case 2: bfd_put_16 (abfd, value, buf); break; | |
177 | case 4: bfd_put_32 (abfd, value, buf); break; | |
178 | case 8: bfd_put_64 (abfd, value, buf); break; | |
179 | default: BFD_FAIL (); | |
180 | } | |
181 | } | |
182 | ||
65765700 JJ |
183 | /* Return zero if C1 and C2 CIEs can be merged. */ |
184 | ||
185 | static | |
186 | int cie_compare (c1, c2) | |
187 | struct cie *c1, *c2; | |
188 | { | |
189 | if (c1->hdr.length == c2->hdr.length | |
190 | && c1->version == c2->version | |
191 | && strcmp (c1->augmentation, c2->augmentation) == 0 | |
192 | && strcmp (c1->augmentation, "eh") != 0 | |
193 | && c1->code_align == c2->code_align | |
194 | && c1->data_align == c2->data_align | |
195 | && c1->ra_column == c2->ra_column | |
196 | && c1->augmentation_size == c2->augmentation_size | |
197 | && c1->personality == c2->personality | |
198 | && c1->per_encoding == c2->per_encoding | |
199 | && c1->lsda_encoding == c2->lsda_encoding | |
200 | && c1->fde_encoding == c2->fde_encoding | |
201 | && (c1->initial_insn_length | |
202 | == c2->initial_insn_length) | |
203 | && memcmp (c1->initial_instructions, | |
204 | c2->initial_instructions, | |
205 | c1->initial_insn_length) == 0) | |
206 | return 0; | |
207 | ||
208 | return 1; | |
209 | } | |
210 | ||
211 | /* This function is called for each input file before the .eh_frame | |
212 | section is relocated. It discards duplicate CIEs and FDEs for discarded | |
213 | functions. The function returns true iff any entries have been | |
214 | deleted. */ | |
215 | ||
216 | boolean | |
126495ed | 217 | _bfd_elf_discard_section_eh_frame (abfd, info, sec, |
65765700 JJ |
218 | reloc_symbol_deleted_p, cookie) |
219 | bfd *abfd; | |
220 | struct bfd_link_info *info; | |
126495ed | 221 | asection *sec; |
8c2ab17d | 222 | boolean (*reloc_symbol_deleted_p) PARAMS ((bfd_vma, PTR)); |
65765700 JJ |
223 | struct elf_reloc_cookie *cookie; |
224 | { | |
225 | bfd_byte *ehbuf = NULL, *buf; | |
226 | bfd_byte *last_cie, *last_fde; | |
227 | struct cie_header hdr; | |
228 | struct cie cie; | |
126495ed | 229 | struct elf_link_hash_table *htab; |
65765700 | 230 | struct eh_frame_hdr_info *hdr_info; |
68f69152 | 231 | struct eh_frame_sec_info *sec_info = NULL; |
65765700 | 232 | unsigned int leb128_tmp; |
9e2a4898 JJ |
233 | unsigned int cie_usage_count, last_cie_ndx, i, offset; |
234 | unsigned int make_relative, make_lsda_relative; | |
65765700 JJ |
235 | bfd_size_type new_size; |
236 | unsigned int ptr_size; | |
237 | ||
238 | if (sec->_raw_size == 0) | |
239 | { | |
240 | /* This file does not contain .eh_frame information. */ | |
241 | return false; | |
242 | } | |
243 | ||
244 | if ((sec->output_section != NULL | |
245 | && bfd_is_abs_section (sec->output_section))) | |
246 | { | |
247 | /* At least one of the sections is being discarded from the | |
248 | link, so we should just ignore them. */ | |
249 | return false; | |
250 | } | |
251 | ||
126495ed AM |
252 | htab = elf_hash_table (info); |
253 | hdr_info = &htab->eh_info; | |
68f69152 | 254 | |
65765700 JJ |
255 | /* Read the frame unwind information from abfd. */ |
256 | ||
257 | ehbuf = (bfd_byte *) bfd_malloc (sec->_raw_size); | |
68f69152 JJ |
258 | if (ehbuf == NULL) |
259 | goto free_no_table; | |
260 | ||
261 | if (! bfd_get_section_contents (abfd, sec, ehbuf, (bfd_vma) 0, | |
262 | sec->_raw_size)) | |
263 | goto free_no_table; | |
65765700 JJ |
264 | |
265 | if (sec->_raw_size >= 4 | |
266 | && bfd_get_32 (abfd, ehbuf) == 0 | |
267 | && cookie->rel == cookie->relend) | |
268 | { | |
269 | /* Empty .eh_frame section. */ | |
270 | free (ehbuf); | |
271 | return false; | |
272 | } | |
273 | ||
65765700 JJ |
274 | /* If .eh_frame section size doesn't fit into int, we cannot handle |
275 | it (it would need to use 64-bit .eh_frame format anyway). */ | |
276 | if (sec->_raw_size != (unsigned int) sec->_raw_size) | |
68f69152 | 277 | goto free_no_table; |
65765700 JJ |
278 | |
279 | ptr_size = (elf_elfheader (abfd)->e_ident[EI_CLASS] | |
280 | == ELFCLASS64) ? 8 : 4; | |
281 | buf = ehbuf; | |
282 | last_cie = NULL; | |
283 | last_cie_ndx = 0; | |
284 | memset (&cie, 0, sizeof (cie)); | |
285 | cie_usage_count = 0; | |
286 | new_size = sec->_raw_size; | |
287 | make_relative = hdr_info->last_cie.make_relative; | |
9e2a4898 | 288 | make_lsda_relative = hdr_info->last_cie.make_lsda_relative; |
65765700 JJ |
289 | sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info) |
290 | + 99 * sizeof (struct eh_cie_fde)); | |
291 | if (sec_info == NULL) | |
292 | goto free_no_table; | |
293 | sec_info->alloced = 100; | |
294 | ||
295 | #define ENSURE_NO_RELOCS(buf) \ | |
296 | if (cookie->rel < cookie->relend \ | |
297 | && (cookie->rel->r_offset \ | |
73722af0 AM |
298 | < (bfd_size_type) ((buf) - ehbuf)) \ |
299 | && cookie->rel->r_info != 0) \ | |
65765700 JJ |
300 | goto free_no_table |
301 | ||
302 | #define SKIP_RELOCS(buf) \ | |
303 | while (cookie->rel < cookie->relend \ | |
304 | && (cookie->rel->r_offset \ | |
305 | < (bfd_size_type) ((buf) - ehbuf))) \ | |
306 | cookie->rel++ | |
307 | ||
308 | #define GET_RELOC(buf) \ | |
309 | ((cookie->rel < cookie->relend \ | |
310 | && (cookie->rel->r_offset \ | |
311 | == (bfd_size_type) ((buf) - ehbuf))) \ | |
312 | ? cookie->rel : NULL) | |
313 | ||
314 | for (;;) | |
315 | { | |
316 | unsigned char *aug; | |
317 | ||
318 | if (sec_info->count == sec_info->alloced) | |
319 | { | |
320 | sec_info = bfd_realloc (sec_info, | |
321 | sizeof (struct eh_frame_sec_info) | |
322 | + (sec_info->alloced + 99) | |
323 | * sizeof (struct eh_cie_fde)); | |
324 | if (sec_info == NULL) | |
325 | goto free_no_table; | |
326 | ||
327 | memset (&sec_info->entry[sec_info->alloced], 0, | |
328 | 100 * sizeof (struct eh_cie_fde)); | |
329 | sec_info->alloced += 100; | |
330 | } | |
331 | ||
332 | last_fde = buf; | |
333 | /* If we are at the end of the section, we still need to decide | |
334 | on whether to output or discard last encountered CIE (if any). */ | |
335 | if ((bfd_size_type) (buf - ehbuf) == sec->_raw_size) | |
336 | hdr.id = (unsigned int) -1; | |
337 | else | |
338 | { | |
339 | if ((bfd_size_type) (buf + 4 - ehbuf) > sec->_raw_size) | |
340 | /* No space for CIE/FDE header length. */ | |
341 | goto free_no_table; | |
342 | ||
343 | hdr.length = bfd_get_32 (abfd, buf); | |
344 | if (hdr.length == 0xffffffff) | |
345 | /* 64-bit .eh_frame is not supported. */ | |
346 | goto free_no_table; | |
347 | buf += 4; | |
e68cc12e | 348 | if ((bfd_size_type) (buf - ehbuf) + hdr.length > sec->_raw_size) |
65765700 JJ |
349 | /* CIE/FDE not contained fully in this .eh_frame input section. */ |
350 | goto free_no_table; | |
351 | ||
352 | sec_info->entry[sec_info->count].offset = last_fde - ehbuf; | |
353 | sec_info->entry[sec_info->count].size = 4 + hdr.length; | |
354 | ||
355 | if (hdr.length == 0) | |
356 | { | |
357 | /* CIE with length 0 must be only the last in the section. */ | |
358 | if ((bfd_size_type) (buf - ehbuf) < sec->_raw_size) | |
359 | goto free_no_table; | |
360 | ENSURE_NO_RELOCS (buf); | |
361 | sec_info->count++; | |
362 | /* Now just finish last encountered CIE processing and break | |
363 | the loop. */ | |
364 | hdr.id = (unsigned int) -1; | |
365 | } | |
366 | else | |
367 | { | |
368 | hdr.id = bfd_get_32 (abfd, buf); | |
369 | buf += 4; | |
370 | if (hdr.id == (unsigned int) -1) | |
371 | goto free_no_table; | |
372 | } | |
373 | } | |
374 | ||
375 | if (hdr.id == 0 || hdr.id == (unsigned int) -1) | |
376 | { | |
377 | unsigned int initial_insn_length; | |
378 | ||
379 | /* CIE */ | |
380 | if (last_cie != NULL) | |
381 | { | |
73722af0 AM |
382 | /* Now check if this CIE is identical to the last CIE, |
383 | in which case we can remove it provided we adjust | |
384 | all FDEs. Also, it can be removed if we have removed | |
385 | all FDEs using it. */ | |
386 | if ((!info->relocateable | |
387 | && cie_compare (&cie, &hdr_info->last_cie) == 0) | |
65765700 JJ |
388 | || cie_usage_count == 0) |
389 | { | |
390 | new_size -= cie.hdr.length + 4; | |
391 | sec_info->entry[last_cie_ndx].removed = 1; | |
392 | sec_info->entry[last_cie_ndx].sec = hdr_info->last_cie_sec; | |
393 | sec_info->entry[last_cie_ndx].new_offset | |
394 | = hdr_info->last_cie_offset; | |
395 | } | |
396 | else | |
397 | { | |
398 | hdr_info->last_cie = cie; | |
399 | hdr_info->last_cie_sec = sec; | |
400 | hdr_info->last_cie_offset = last_cie - ehbuf; | |
401 | sec_info->entry[last_cie_ndx].make_relative | |
402 | = cie.make_relative; | |
9e2a4898 JJ |
403 | sec_info->entry[last_cie_ndx].make_lsda_relative |
404 | = cie.make_lsda_relative; | |
09ae86c2 JJ |
405 | sec_info->entry[last_cie_ndx].per_encoding_relative |
406 | = (cie.per_encoding & 0x70) == DW_EH_PE_pcrel; | |
65765700 JJ |
407 | } |
408 | } | |
409 | ||
410 | if (hdr.id == (unsigned int) -1) | |
411 | break; | |
412 | ||
413 | last_cie_ndx = sec_info->count; | |
414 | sec_info->entry[sec_info->count].cie = 1; | |
415 | ||
416 | cie_usage_count = 0; | |
417 | memset (&cie, 0, sizeof (cie)); | |
418 | cie.hdr = hdr; | |
419 | cie.version = *buf++; | |
420 | ||
421 | /* Cannot handle unknown versions. */ | |
422 | if (cie.version != 1) | |
423 | goto free_no_table; | |
424 | if (strlen (buf) > sizeof (cie.augmentation) - 1) | |
425 | goto free_no_table; | |
426 | ||
427 | strcpy (cie.augmentation, buf); | |
428 | buf = strchr (buf, '\0') + 1; | |
429 | ENSURE_NO_RELOCS (buf); | |
430 | if (buf[0] == 'e' && buf[1] == 'h') | |
431 | { | |
432 | /* GCC < 3.0 .eh_frame CIE */ | |
433 | /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__ | |
434 | is private to each CIE, so we don't need it for anything. | |
435 | Just skip it. */ | |
436 | buf += ptr_size; | |
437 | SKIP_RELOCS (buf); | |
438 | } | |
439 | read_uleb128 (cie.code_align, buf); | |
440 | read_sleb128 (cie.data_align, buf); | |
7e326afc NC |
441 | /* Note - in DWARF2 the return address column is an unsigned byte. |
442 | In DWARF3 it is a ULEB128. We are following DWARF3. For most | |
443 | ports this will not matter as the value will be less than 128. | |
444 | For the others (eg FRV, SH, MMIX, IA64) they need a fixed GCC | |
445 | which conforms to the DWARF3 standard. */ | |
446 | read_uleb128 (cie.ra_column, buf); | |
65765700 JJ |
447 | ENSURE_NO_RELOCS (buf); |
448 | cie.lsda_encoding = DW_EH_PE_omit; | |
449 | cie.fde_encoding = DW_EH_PE_omit; | |
450 | cie.per_encoding = DW_EH_PE_omit; | |
451 | aug = cie.augmentation; | |
452 | if (aug[0] != 'e' || aug[1] != 'h') | |
453 | { | |
454 | if (*aug == 'z') | |
455 | { | |
456 | aug++; | |
457 | read_uleb128 (cie.augmentation_size, buf); | |
458 | ENSURE_NO_RELOCS (buf); | |
459 | } | |
460 | ||
461 | while (*aug != '\0') | |
462 | switch (*aug++) | |
463 | { | |
464 | case 'L': | |
465 | cie.lsda_encoding = *buf++; | |
466 | ENSURE_NO_RELOCS (buf); | |
467 | if (get_DW_EH_PE_width (cie.lsda_encoding, ptr_size) == 0) | |
468 | goto free_no_table; | |
469 | break; | |
470 | case 'R': | |
471 | cie.fde_encoding = *buf++; | |
472 | ENSURE_NO_RELOCS (buf); | |
473 | if (get_DW_EH_PE_width (cie.fde_encoding, ptr_size) == 0) | |
474 | goto free_no_table; | |
475 | break; | |
476 | case 'P': | |
477 | { | |
478 | int per_width; | |
479 | ||
480 | cie.per_encoding = *buf++; | |
481 | per_width = get_DW_EH_PE_width (cie.per_encoding, | |
482 | ptr_size); | |
483 | if (per_width == 0) | |
484 | goto free_no_table; | |
485 | if ((cie.per_encoding & 0xf0) == DW_EH_PE_aligned) | |
486 | buf = (ehbuf | |
487 | + ((buf - ehbuf + per_width - 1) | |
488 | & ~((bfd_size_type) per_width - 1))); | |
489 | ENSURE_NO_RELOCS (buf); | |
65765700 JJ |
490 | /* Ensure we have a reloc here, against |
491 | a global symbol. */ | |
99eb2ac8 | 492 | if (GET_RELOC (buf) != NULL) |
65765700 JJ |
493 | { |
494 | unsigned long r_symndx; | |
495 | ||
496 | #ifdef BFD64 | |
497 | if (ptr_size == 8) | |
498 | r_symndx = ELF64_R_SYM (cookie->rel->r_info); | |
499 | else | |
500 | #endif | |
501 | r_symndx = ELF32_R_SYM (cookie->rel->r_info); | |
502 | if (r_symndx >= cookie->locsymcount) | |
503 | { | |
504 | struct elf_link_hash_entry *h; | |
505 | ||
506 | r_symndx -= cookie->extsymoff; | |
507 | h = cookie->sym_hashes[r_symndx]; | |
508 | ||
509 | while (h->root.type == bfd_link_hash_indirect | |
510 | || h->root.type == bfd_link_hash_warning) | |
511 | h = (struct elf_link_hash_entry *) | |
512 | h->root.u.i.link; | |
513 | ||
514 | cie.personality = h; | |
515 | } | |
516 | cookie->rel++; | |
517 | } | |
518 | buf += per_width; | |
519 | } | |
520 | break; | |
521 | default: | |
522 | /* Unrecognized augmentation. Better bail out. */ | |
523 | goto free_no_table; | |
524 | } | |
525 | } | |
526 | ||
527 | /* For shared libraries, try to get rid of as many RELATIVE relocs | |
0bb2d96a JJ |
528 | as possible. */ |
529 | if (info->shared | |
65765700 JJ |
530 | && (cie.fde_encoding & 0xf0) == DW_EH_PE_absptr) |
531 | cie.make_relative = 1; | |
532 | ||
0bb2d96a | 533 | if (info->shared |
9e2a4898 JJ |
534 | && (cie.lsda_encoding & 0xf0) == DW_EH_PE_absptr) |
535 | cie.make_lsda_relative = 1; | |
536 | ||
65765700 JJ |
537 | /* If FDE encoding was not specified, it defaults to |
538 | DW_EH_absptr. */ | |
539 | if (cie.fde_encoding == DW_EH_PE_omit) | |
540 | cie.fde_encoding = DW_EH_PE_absptr; | |
541 | ||
542 | initial_insn_length = cie.hdr.length - (buf - last_fde - 4); | |
543 | if (initial_insn_length <= 50) | |
544 | { | |
545 | cie.initial_insn_length = initial_insn_length; | |
546 | memcpy (cie.initial_instructions, buf, initial_insn_length); | |
547 | } | |
548 | buf += initial_insn_length; | |
549 | ENSURE_NO_RELOCS (buf); | |
550 | last_cie = last_fde; | |
551 | } | |
552 | else | |
553 | { | |
554 | /* Ensure this FDE uses the last CIE encountered. */ | |
555 | if (last_cie == NULL | |
556 | || hdr.id != (unsigned int) (buf - 4 - last_cie)) | |
557 | goto free_no_table; | |
558 | ||
559 | ENSURE_NO_RELOCS (buf); | |
99eb2ac8 | 560 | if (GET_RELOC (buf) == NULL) |
65765700 JJ |
561 | /* This should not happen. */ |
562 | goto free_no_table; | |
563 | if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie)) | |
564 | { | |
73722af0 | 565 | /* This is a FDE against a discarded section. It should |
65765700 JJ |
566 | be deleted. */ |
567 | new_size -= hdr.length + 4; | |
568 | sec_info->entry[sec_info->count].removed = 1; | |
569 | } | |
570 | else | |
571 | { | |
0bb2d96a | 572 | if (info->shared |
af40ce3c JJ |
573 | && (((cie.fde_encoding & 0xf0) == DW_EH_PE_absptr |
574 | && cie.make_relative == 0) | |
575 | || (cie.fde_encoding & 0xf0) == DW_EH_PE_aligned)) | |
0bb2d96a | 576 | { |
73722af0 | 577 | /* If a shared library uses absolute pointers |
0bb2d96a JJ |
578 | which we cannot turn into PC relative, |
579 | don't create the binary search table, | |
580 | since it is affected by runtime relocations. */ | |
581 | hdr_info->table = false; | |
582 | } | |
65765700 JJ |
583 | cie_usage_count++; |
584 | hdr_info->fde_count++; | |
585 | } | |
9e2a4898 JJ |
586 | if (cie.lsda_encoding != DW_EH_PE_omit) |
587 | { | |
588 | unsigned int dummy; | |
589 | ||
590 | aug = buf; | |
591 | buf += 2 * get_DW_EH_PE_width (cie.fde_encoding, ptr_size); | |
592 | if (cie.augmentation[0] == 'z') | |
593 | read_uleb128 (dummy, buf); | |
594 | /* If some new augmentation data is added before LSDA | |
595 | in FDE augmentation area, this need to be adjusted. */ | |
596 | sec_info->entry[sec_info->count].lsda_offset = (buf - aug); | |
597 | } | |
65765700 JJ |
598 | buf = last_fde + 4 + hdr.length; |
599 | SKIP_RELOCS (buf); | |
600 | } | |
601 | ||
602 | sec_info->entry[sec_info->count].fde_encoding = cie.fde_encoding; | |
9e2a4898 | 603 | sec_info->entry[sec_info->count].lsda_encoding = cie.lsda_encoding; |
65765700 JJ |
604 | sec_info->count++; |
605 | } | |
606 | ||
607 | elf_section_data (sec)->sec_info = sec_info; | |
608 | elf_section_data (sec)->sec_info_type = ELF_INFO_TYPE_EH_FRAME; | |
609 | ||
610 | /* Ok, now we can assign new offsets. */ | |
611 | offset = 0; | |
612 | last_cie_ndx = 0; | |
613 | for (i = 0; i < sec_info->count; i++) | |
614 | { | |
615 | if (! sec_info->entry[i].removed) | |
616 | { | |
617 | sec_info->entry[i].new_offset = offset; | |
618 | offset += sec_info->entry[i].size; | |
619 | if (sec_info->entry[i].cie) | |
620 | { | |
621 | last_cie_ndx = i; | |
622 | make_relative = sec_info->entry[i].make_relative; | |
9e2a4898 | 623 | make_lsda_relative = sec_info->entry[i].make_lsda_relative; |
65765700 JJ |
624 | } |
625 | else | |
9e2a4898 JJ |
626 | { |
627 | sec_info->entry[i].make_relative = make_relative; | |
628 | sec_info->entry[i].make_lsda_relative = make_lsda_relative; | |
09ae86c2 | 629 | sec_info->entry[i].per_encoding_relative = 0; |
9e2a4898 | 630 | } |
65765700 JJ |
631 | } |
632 | else if (sec_info->entry[i].cie && sec_info->entry[i].sec == sec) | |
633 | { | |
634 | /* Need to adjust new_offset too. */ | |
635 | BFD_ASSERT (sec_info->entry[last_cie_ndx].offset | |
636 | == sec_info->entry[i].new_offset); | |
637 | sec_info->entry[i].new_offset | |
638 | = sec_info->entry[last_cie_ndx].new_offset; | |
639 | } | |
640 | } | |
641 | if (hdr_info->last_cie_sec == sec) | |
642 | { | |
643 | BFD_ASSERT (sec_info->entry[last_cie_ndx].offset | |
644 | == hdr_info->last_cie_offset); | |
645 | hdr_info->last_cie_offset = sec_info->entry[last_cie_ndx].new_offset; | |
646 | } | |
647 | ||
a5eb27e6 JJ |
648 | /* FIXME: Currently it is not possible to shrink sections to zero size at |
649 | this point, so build a fake minimal CIE. */ | |
650 | if (new_size == 0) | |
651 | new_size = 16; | |
652 | ||
65765700 | 653 | /* Shrink the sec as needed. */ |
65765700 JJ |
654 | sec->_cooked_size = new_size; |
655 | if (sec->_cooked_size == 0) | |
656 | sec->flags |= SEC_EXCLUDE; | |
657 | ||
68f69152 | 658 | free (ehbuf); |
65765700 JJ |
659 | return new_size != sec->_raw_size; |
660 | ||
661 | free_no_table: | |
68f69152 JJ |
662 | if (ehbuf) |
663 | free (ehbuf); | |
65765700 JJ |
664 | if (sec_info) |
665 | free (sec_info); | |
666 | hdr_info->table = false; | |
667 | hdr_info->last_cie.hdr.length = 0; | |
668 | return false; | |
669 | } | |
670 | ||
671 | /* This function is called for .eh_frame_hdr section after | |
672 | _bfd_elf_discard_section_eh_frame has been called on all .eh_frame | |
673 | input sections. It finalizes the size of .eh_frame_hdr section. */ | |
674 | ||
675 | boolean | |
126495ed | 676 | _bfd_elf_discard_section_eh_frame_hdr (abfd, info) |
65765700 JJ |
677 | bfd *abfd; |
678 | struct bfd_link_info *info; | |
65765700 | 679 | { |
126495ed | 680 | struct elf_link_hash_table *htab; |
65765700 | 681 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 682 | asection *sec; |
65765700 | 683 | |
126495ed AM |
684 | htab = elf_hash_table (info); |
685 | hdr_info = &htab->eh_info; | |
686 | sec = hdr_info->hdr_sec; | |
687 | if (sec == NULL) | |
68f69152 | 688 | return false; |
126495ed | 689 | |
65765700 JJ |
690 | sec->_cooked_size = EH_FRAME_HDR_SIZE; |
691 | if (hdr_info->table) | |
692 | sec->_cooked_size += 4 + hdr_info->fde_count * 8; | |
693 | ||
694 | /* Request program headers to be recalculated. */ | |
695 | elf_tdata (abfd)->program_header_size = 0; | |
126495ed | 696 | elf_tdata (abfd)->eh_frame_hdr = sec; |
65765700 JJ |
697 | return true; |
698 | } | |
699 | ||
68f69152 JJ |
700 | /* This function is called from size_dynamic_sections. |
701 | It needs to decide whether .eh_frame_hdr should be output or not, | |
702 | because later on it is too late for calling _bfd_strip_section_from_output, | |
703 | since dynamic symbol table has been sized. */ | |
704 | ||
705 | boolean | |
706 | _bfd_elf_maybe_strip_eh_frame_hdr (info) | |
707 | struct bfd_link_info *info; | |
708 | { | |
126495ed | 709 | asection *o; |
68f69152 | 710 | bfd *abfd; |
126495ed | 711 | struct elf_link_hash_table *htab; |
68f69152 JJ |
712 | struct eh_frame_hdr_info *hdr_info; |
713 | ||
126495ed AM |
714 | htab = elf_hash_table (info); |
715 | hdr_info = &htab->eh_info; | |
716 | if (hdr_info->hdr_sec == NULL) | |
68f69152 JJ |
717 | return true; |
718 | ||
126495ed AM |
719 | if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)) |
720 | { | |
721 | hdr_info->hdr_sec = NULL; | |
722 | return true; | |
723 | } | |
68f69152 JJ |
724 | |
725 | abfd = NULL; | |
726 | if (info->eh_frame_hdr) | |
727 | for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next) | |
728 | { | |
729 | /* Count only sections which have at least a single CIE or FDE. | |
730 | There cannot be any CIE or FDE <= 8 bytes. */ | |
731 | o = bfd_get_section_by_name (abfd, ".eh_frame"); | |
2d653fc7 | 732 | if (o && o->_raw_size > 8 && !bfd_is_abs_section (o->output_section)) |
68f69152 JJ |
733 | break; |
734 | } | |
735 | ||
736 | if (abfd == NULL) | |
737 | { | |
126495ed AM |
738 | _bfd_strip_section_from_output (info, hdr_info->hdr_sec); |
739 | hdr_info->hdr_sec = NULL; | |
740 | return true; | |
68f69152 | 741 | } |
126495ed AM |
742 | |
743 | hdr_info->table = true; | |
68f69152 JJ |
744 | return true; |
745 | } | |
746 | ||
65765700 JJ |
747 | /* Adjust an address in the .eh_frame section. Given OFFSET within |
748 | SEC, this returns the new offset in the adjusted .eh_frame section, | |
749 | or -1 if the address refers to a CIE/FDE which has been removed | |
750 | or to offset with dynamic relocation which is no longer needed. */ | |
751 | ||
752 | bfd_vma | |
753 | _bfd_elf_eh_frame_section_offset (output_bfd, sec, offset) | |
754 | bfd *output_bfd ATTRIBUTE_UNUSED; | |
755 | asection *sec; | |
756 | bfd_vma offset; | |
757 | { | |
758 | struct eh_frame_sec_info *sec_info; | |
759 | unsigned int lo, hi, mid; | |
760 | ||
761 | if (elf_section_data (sec)->sec_info_type != ELF_INFO_TYPE_EH_FRAME) | |
762 | return offset; | |
763 | sec_info = (struct eh_frame_sec_info *) | |
764 | elf_section_data (sec)->sec_info; | |
765 | ||
766 | if (offset >= sec->_raw_size) | |
767 | return offset - (sec->_cooked_size - sec->_raw_size); | |
768 | ||
769 | lo = 0; | |
770 | hi = sec_info->count; | |
771 | mid = 0; | |
772 | while (lo < hi) | |
773 | { | |
774 | mid = (lo + hi) / 2; | |
775 | if (offset < sec_info->entry[mid].offset) | |
776 | hi = mid; | |
777 | else if (offset | |
778 | >= sec_info->entry[mid].offset + sec_info->entry[mid].size) | |
779 | lo = mid + 1; | |
780 | else | |
781 | break; | |
782 | } | |
783 | ||
784 | BFD_ASSERT (lo < hi); | |
785 | ||
786 | /* FDE or CIE was removed. */ | |
787 | if (sec_info->entry[mid].removed) | |
788 | return (bfd_vma) -1; | |
789 | ||
790 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time | |
791 | relocation against FDE's initial_location field. */ | |
792 | if (sec_info->entry[mid].make_relative | |
793 | && ! sec_info->entry[mid].cie | |
794 | && offset == sec_info->entry[mid].offset + 8) | |
0bb2d96a | 795 | return (bfd_vma) -2; |
65765700 | 796 | |
9e2a4898 JJ |
797 | /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need |
798 | for run-time relocation against LSDA field. */ | |
799 | if (sec_info->entry[mid].make_lsda_relative | |
800 | && ! sec_info->entry[mid].cie | |
126495ed AM |
801 | && (offset == (sec_info->entry[mid].offset + 8 |
802 | + sec_info->entry[mid].lsda_offset))) | |
0bb2d96a | 803 | return (bfd_vma) -2; |
9e2a4898 | 804 | |
c68836a9 AM |
805 | return (offset + sec_info->entry[mid].new_offset |
806 | - sec_info->entry[mid].offset); | |
65765700 JJ |
807 | } |
808 | ||
809 | /* Write out .eh_frame section. This is called with the relocated | |
810 | contents. */ | |
811 | ||
812 | boolean | |
126495ed | 813 | _bfd_elf_write_section_eh_frame (abfd, info, sec, contents) |
65765700 | 814 | bfd *abfd; |
126495ed AM |
815 | struct bfd_link_info *info; |
816 | asection *sec; | |
65765700 JJ |
817 | bfd_byte *contents; |
818 | { | |
819 | struct eh_frame_sec_info *sec_info; | |
126495ed | 820 | struct elf_link_hash_table *htab; |
65765700 JJ |
821 | struct eh_frame_hdr_info *hdr_info; |
822 | unsigned int i; | |
823 | bfd_byte *p, *buf; | |
824 | unsigned int leb128_tmp; | |
825 | unsigned int cie_offset = 0; | |
826 | unsigned int ptr_size; | |
827 | ||
828 | ptr_size = (elf_elfheader (sec->owner)->e_ident[EI_CLASS] | |
829 | == ELFCLASS64) ? 8 : 4; | |
830 | ||
831 | if (elf_section_data (sec)->sec_info_type != ELF_INFO_TYPE_EH_FRAME) | |
832 | return bfd_set_section_contents (abfd, sec->output_section, | |
833 | contents, | |
834 | (file_ptr) sec->output_offset, | |
835 | sec->_raw_size); | |
836 | sec_info = (struct eh_frame_sec_info *) | |
837 | elf_section_data (sec)->sec_info; | |
126495ed AM |
838 | htab = elf_hash_table (info); |
839 | hdr_info = &htab->eh_info; | |
840 | if (hdr_info->table && hdr_info->array == NULL) | |
841 | hdr_info->array | |
842 | = bfd_malloc (hdr_info->fde_count * sizeof(*hdr_info->array)); | |
843 | if (hdr_info->array == NULL) | |
844 | hdr_info = NULL; | |
65765700 JJ |
845 | |
846 | p = contents; | |
847 | for (i = 0; i < sec_info->count; ++i) | |
848 | { | |
849 | if (sec_info->entry[i].removed) | |
850 | { | |
851 | if (sec_info->entry[i].cie) | |
852 | { | |
a3aa38ee JJ |
853 | /* If CIE is removed due to no remaining FDEs referencing it |
854 | and there were no CIEs kept before it, sec_info->entry[i].sec | |
855 | will be zero. */ | |
856 | if (sec_info->entry[i].sec == NULL) | |
857 | cie_offset = 0; | |
858 | else | |
859 | { | |
860 | cie_offset = sec_info->entry[i].new_offset; | |
861 | cie_offset += (sec_info->entry[i].sec->output_section->vma | |
862 | + sec_info->entry[i].sec->output_offset | |
863 | - sec->output_section->vma | |
864 | - sec->output_offset); | |
865 | } | |
65765700 JJ |
866 | } |
867 | continue; | |
868 | } | |
a3aa38ee | 869 | |
65765700 JJ |
870 | if (sec_info->entry[i].cie) |
871 | { | |
872 | /* CIE */ | |
873 | cie_offset = sec_info->entry[i].new_offset; | |
9e2a4898 | 874 | if (sec_info->entry[i].make_relative |
09ae86c2 JJ |
875 | || sec_info->entry[i].make_lsda_relative |
876 | || sec_info->entry[i].per_encoding_relative) | |
65765700 JJ |
877 | { |
878 | unsigned char *aug; | |
9e2a4898 | 879 | unsigned int action; |
65765700 JJ |
880 | unsigned int dummy, per_width, per_encoding; |
881 | ||
9e2a4898 | 882 | /* Need to find 'R' or 'L' augmentation's argument and modify |
65765700 | 883 | DW_EH_PE_* value. */ |
9e2a4898 | 884 | action = (sec_info->entry[i].make_relative ? 1 : 0) |
09ae86c2 JJ |
885 | | (sec_info->entry[i].make_lsda_relative ? 2 : 0) |
886 | | (sec_info->entry[i].per_encoding_relative ? 4 : 0); | |
65765700 JJ |
887 | buf = contents + sec_info->entry[i].offset; |
888 | /* Skip length, id and version. */ | |
889 | buf += 9; | |
890 | aug = buf; | |
891 | buf = strchr (buf, '\0') + 1; | |
892 | read_uleb128 (dummy, buf); | |
893 | read_sleb128 (dummy, buf); | |
894 | read_uleb128 (dummy, buf); | |
895 | if (*aug == 'z') | |
896 | { | |
897 | read_uleb128 (dummy, buf); | |
898 | aug++; | |
899 | } | |
900 | ||
9e2a4898 | 901 | while (action) |
65765700 JJ |
902 | switch (*aug++) |
903 | { | |
904 | case 'L': | |
9e2a4898 JJ |
905 | if (action & 2) |
906 | { | |
907 | BFD_ASSERT (*buf == sec_info->entry[i].lsda_encoding); | |
908 | *buf |= DW_EH_PE_pcrel; | |
909 | action &= ~2; | |
910 | } | |
65765700 JJ |
911 | buf++; |
912 | break; | |
913 | case 'P': | |
914 | per_encoding = *buf++; | |
915 | per_width = get_DW_EH_PE_width (per_encoding, | |
916 | ptr_size); | |
917 | BFD_ASSERT (per_width != 0); | |
09ae86c2 JJ |
918 | BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel) |
919 | == sec_info->entry[i].per_encoding_relative); | |
65765700 JJ |
920 | if ((per_encoding & 0xf0) == DW_EH_PE_aligned) |
921 | buf = (contents | |
922 | + ((buf - contents + per_width - 1) | |
923 | & ~((bfd_size_type) per_width - 1))); | |
09ae86c2 JJ |
924 | if (action & 4) |
925 | { | |
926 | bfd_vma value; | |
927 | ||
928 | value = read_value (abfd, buf, per_width); | |
929 | value += (sec_info->entry[i].offset | |
930 | - sec_info->entry[i].new_offset); | |
931 | write_value (abfd, buf, value, per_width); | |
932 | action &= ~4; | |
933 | } | |
65765700 JJ |
934 | buf += per_width; |
935 | break; | |
9e2a4898 JJ |
936 | case 'R': |
937 | if (action & 1) | |
938 | { | |
939 | BFD_ASSERT (*buf == sec_info->entry[i].fde_encoding); | |
940 | *buf |= DW_EH_PE_pcrel; | |
941 | action &= ~1; | |
942 | } | |
943 | buf++; | |
944 | break; | |
65765700 JJ |
945 | default: |
946 | BFD_FAIL (); | |
947 | } | |
65765700 JJ |
948 | } |
949 | } | |
af40ce3c | 950 | else if (sec_info->entry[i].size > 4) |
65765700 JJ |
951 | { |
952 | /* FDE */ | |
953 | bfd_vma value = 0, address; | |
9e2a4898 | 954 | unsigned int width; |
65765700 JJ |
955 | |
956 | buf = contents + sec_info->entry[i].offset; | |
957 | /* Skip length. */ | |
958 | buf += 4; | |
959 | bfd_put_32 (abfd, | |
960 | sec_info->entry[i].new_offset + 4 - cie_offset, buf); | |
961 | buf += 4; | |
9e2a4898 JJ |
962 | width = get_DW_EH_PE_width (sec_info->entry[i].fde_encoding, |
963 | ptr_size); | |
964 | address = value = read_value (abfd, buf, width); | |
965 | if (value) | |
65765700 | 966 | { |
9e2a4898 JJ |
967 | switch (sec_info->entry[i].fde_encoding & 0xf0) |
968 | { | |
969 | case DW_EH_PE_indirect: | |
970 | case DW_EH_PE_textrel: | |
971 | BFD_ASSERT (hdr_info == NULL); | |
972 | break; | |
973 | case DW_EH_PE_datarel: | |
974 | { | |
975 | asection *got = bfd_get_section_by_name (abfd, ".got"); | |
976 | ||
977 | BFD_ASSERT (got != NULL); | |
978 | address += got->vma; | |
979 | } | |
980 | break; | |
981 | case DW_EH_PE_pcrel: | |
982 | value += (sec_info->entry[i].offset | |
983 | - sec_info->entry[i].new_offset); | |
984 | address += (sec->output_section->vma + sec->output_offset | |
985 | + sec_info->entry[i].offset + 8); | |
986 | break; | |
987 | } | |
988 | if (sec_info->entry[i].make_relative) | |
989 | value -= (sec->output_section->vma + sec->output_offset | |
65765700 | 990 | + sec_info->entry[i].new_offset + 8); |
9e2a4898 | 991 | write_value (abfd, buf, value, width); |
65765700 JJ |
992 | } |
993 | ||
994 | if (hdr_info) | |
995 | { | |
996 | hdr_info->array[hdr_info->array_count].initial_loc = address; | |
997 | hdr_info->array[hdr_info->array_count++].fde | |
998 | = (sec->output_section->vma + sec->output_offset | |
999 | + sec_info->entry[i].new_offset); | |
1000 | } | |
9e2a4898 JJ |
1001 | |
1002 | if ((sec_info->entry[i].lsda_encoding & 0xf0) == DW_EH_PE_pcrel | |
1003 | || sec_info->entry[i].make_lsda_relative) | |
1004 | { | |
1005 | buf += sec_info->entry[i].lsda_offset; | |
1006 | width = get_DW_EH_PE_width (sec_info->entry[i].lsda_encoding, | |
1007 | ptr_size); | |
1008 | value = read_value (abfd, buf, width); | |
1009 | if (value) | |
1010 | { | |
1011 | if ((sec_info->entry[i].lsda_encoding & 0xf0) | |
1012 | == DW_EH_PE_pcrel) | |
1013 | value += (sec_info->entry[i].offset | |
1014 | - sec_info->entry[i].new_offset); | |
1015 | else if (sec_info->entry[i].make_lsda_relative) | |
1016 | value -= (sec->output_section->vma + sec->output_offset | |
1017 | + sec_info->entry[i].new_offset + 8 | |
1018 | + sec_info->entry[i].lsda_offset); | |
1019 | write_value (abfd, buf, value, width); | |
1020 | } | |
1021 | } | |
65765700 | 1022 | } |
af40ce3c JJ |
1023 | else |
1024 | /* Terminating FDE must be at the end of .eh_frame section only. */ | |
1025 | BFD_ASSERT (i == sec_info->count - 1); | |
65765700 JJ |
1026 | |
1027 | BFD_ASSERT (p == contents + sec_info->entry[i].new_offset); | |
1028 | memmove (p, contents + sec_info->entry[i].offset, | |
1029 | sec_info->entry[i].size); | |
1030 | p += sec_info->entry[i].size; | |
1031 | } | |
1032 | ||
a5eb27e6 JJ |
1033 | /* FIXME: Once _bfd_elf_discard_section_eh_frame will be able to |
1034 | shrink sections to zero size, this won't be needed any more. */ | |
1035 | if (p == contents && sec->_cooked_size == 16) | |
1036 | { | |
1037 | bfd_put_32 (abfd, 12, p); /* Fake CIE length */ | |
1038 | bfd_put_32 (abfd, 0, p + 4); /* Fake CIE id */ | |
1039 | p[8] = 1; /* Fake CIE version */ | |
1040 | memset (p + 9, 0, 7); /* Fake CIE augmentation, 3xleb128 | |
1041 | and 3xDW_CFA_nop as pad */ | |
1042 | p += 16; | |
1043 | } | |
1044 | ||
65765700 JJ |
1045 | BFD_ASSERT ((bfd_size_type) (p - contents) == sec->_cooked_size); |
1046 | ||
1047 | return bfd_set_section_contents (abfd, sec->output_section, | |
1048 | contents, (file_ptr) sec->output_offset, | |
1049 | sec->_cooked_size); | |
1050 | } | |
1051 | ||
1052 | /* Helper function used to sort .eh_frame_hdr search table by increasing | |
1053 | VMA of FDE initial location. */ | |
1054 | ||
1055 | static int | |
1056 | vma_compare (a, b) | |
1057 | const PTR a; | |
1058 | const PTR b; | |
1059 | { | |
1060 | struct eh_frame_array_ent *p = (struct eh_frame_array_ent *) a; | |
1061 | struct eh_frame_array_ent *q = (struct eh_frame_array_ent *) b; | |
1062 | if (p->initial_loc > q->initial_loc) | |
1063 | return 1; | |
1064 | if (p->initial_loc < q->initial_loc) | |
1065 | return -1; | |
1066 | return 0; | |
1067 | } | |
1068 | ||
1069 | /* Write out .eh_frame_hdr section. This must be called after | |
1070 | _bfd_elf_write_section_eh_frame has been called on all input | |
1071 | .eh_frame sections. | |
1072 | .eh_frame_hdr format: | |
1073 | ubyte version (currently 1) | |
1074 | ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of | |
1075 | .eh_frame section) | |
1076 | ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count | |
1077 | number (or DW_EH_PE_omit if there is no | |
1078 | binary search table computed)) | |
1079 | ubyte table_enc (DW_EH_PE_* encoding of binary search table, | |
1080 | or DW_EH_PE_omit if not present. | |
1081 | DW_EH_PE_datarel is using address of | |
1082 | .eh_frame_hdr section start as base) | |
1083 | [encoded] eh_frame_ptr (pointer to start of .eh_frame section) | |
1084 | optionally followed by: | |
1085 | [encoded] fde_count (total number of FDEs in .eh_frame section) | |
1086 | fde_count x [encoded] initial_loc, fde | |
1087 | (array of encoded pairs containing | |
1088 | FDE initial_location field and FDE address, | |
1089 | sorted by increasing initial_loc) */ | |
1090 | ||
1091 | boolean | |
126495ed | 1092 | _bfd_elf_write_section_eh_frame_hdr (abfd, info) |
65765700 | 1093 | bfd *abfd; |
126495ed | 1094 | struct bfd_link_info *info; |
65765700 | 1095 | { |
126495ed | 1096 | struct elf_link_hash_table *htab; |
65765700 | 1097 | struct eh_frame_hdr_info *hdr_info; |
126495ed | 1098 | asection *sec; |
65765700 JJ |
1099 | bfd_byte *contents; |
1100 | asection *eh_frame_sec; | |
1101 | bfd_size_type size; | |
1102 | ||
126495ed AM |
1103 | htab = elf_hash_table (info); |
1104 | hdr_info = &htab->eh_info; | |
1105 | sec = hdr_info->hdr_sec; | |
1106 | if (sec == NULL) | |
57a72197 JJ |
1107 | return true; |
1108 | ||
65765700 JJ |
1109 | size = EH_FRAME_HDR_SIZE; |
1110 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) | |
1111 | size += 4 + hdr_info->fde_count * 8; | |
1112 | contents = bfd_malloc (size); | |
1113 | if (contents == NULL) | |
1114 | return false; | |
1115 | ||
1116 | eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame"); | |
1117 | if (eh_frame_sec == NULL) | |
1118 | return false; | |
1119 | ||
1120 | memset (contents, 0, EH_FRAME_HDR_SIZE); | |
1121 | contents[0] = 1; /* Version */ | |
1122 | contents[1] = DW_EH_PE_pcrel | DW_EH_PE_sdata4; /* .eh_frame offset */ | |
1123 | if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count) | |
1124 | { | |
1125 | contents[2] = DW_EH_PE_udata4; /* FDE count encoding */ | |
1126 | contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; /* search table enc */ | |
1127 | } | |
1128 | else | |
1129 | { | |
1130 | contents[2] = DW_EH_PE_omit; | |
1131 | contents[3] = DW_EH_PE_omit; | |
1132 | } | |
1133 | bfd_put_32 (abfd, eh_frame_sec->vma - sec->output_section->vma - 4, | |
1134 | contents + 4); | |
1135 | if (contents[2] != DW_EH_PE_omit) | |
1136 | { | |
1137 | unsigned int i; | |
1138 | ||
1139 | bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE); | |
1140 | qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array), | |
1141 | vma_compare); | |
1142 | for (i = 0; i < hdr_info->fde_count; i++) | |
1143 | { | |
1144 | bfd_put_32 (abfd, | |
1145 | hdr_info->array[i].initial_loc | |
1146 | - sec->output_section->vma, | |
1147 | contents + EH_FRAME_HDR_SIZE + i * 8 + 4); | |
1148 | bfd_put_32 (abfd, | |
1149 | hdr_info->array[i].fde - sec->output_section->vma, | |
1150 | contents + EH_FRAME_HDR_SIZE + i * 8 + 8); | |
1151 | } | |
1152 | } | |
1153 | ||
1154 | return bfd_set_section_contents (abfd, sec->output_section, | |
1155 | contents, (file_ptr) sec->output_offset, | |
1156 | sec->_cooked_size); | |
1157 | } |